JN Soundboard - An open-source hotkey soundboard program
Jingle Palette - Jingle Palette application was designed to be an instant jingle player for radio broadcast studios.
CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)
Farrago - Intuitive soundboard app to quickly play sound bites, audio effects, and music clips.
Soundplant - Play sound files with the computer keyboard
Sound Show - Sound Show is a soundboard application that you can utilize for your project and customize according to requirements.